Substance P selectively activates TNF-alpha gene expression in murine mast cells

There is increasing evidence that the neurologic system is capable of modulating a wide range of immunologic responses, including certain inflammatory processes in the lung, gastrointestinal tract, and skin. It has been proposed that secreted neuropeptides such as substance P (SP) may mediate these neuroinflammatory interactions by binding to and stimulating immune cells such as mast cells and lymphoid cells. SP is secreted in a variety of tissues by an extensive network of neurosensory C and A5 fibers in response to a wide range of noxious stimuli and injury. Previous studies to examine the effect of SP on mast cells have focused on its role in triggering histamine release and mediating immediate hypersensitivity responses. Recently it was demonstrated that mast cells are also capable of secreting multiple cytokines including TNF-alpha, IL-1, IL-3, IL-4, IL-6, and GM-CSF. In this study we tested the possibility that SP may also influence mast cell-mediated late inflammatory events by modulating the production of one or several of these cytokines. Our results indicate that SP induces TNF-alpha mRNA expression and TNF-alpha secretion in a dose-dependent manner in a murine mast cell line, CFTL12. Likewise, SP stimulates TNF-alpha secretion in freshly isolated murine peritoneal mast cells. The induction of mast cell TNF-alpha is selective, since SP does not stimulate the production of IL-1, IL-3, IL-4, IL-6, or GM-CSF in these cells. The CFTL 12 mast cell line constitutively expresses high levels of SP receptor mRNA which is not modulated by PMA/cycloheximide treatment or SP. These results further support the concept that the neurologic system modulates inflammatory events by neuropeptide-mediated mast cell cytokine release.

Milk production in Brahman and Angus cows on endophyte-infected fescue and common bermudagrass

Daily milk yield and milk fat were estimated by method of milking machine in 60 Angus and 60 Brahman cows grazing common bermudagrass or endophyte-infected fescue during a 3-yr period. Averaged over monthly estimates, there was evidence (P < .05) of a dam breed x forage interaction in daily milk yield. Tall fescue decreased milk yield more in the Angus (1.64 kg/d, P < .01) than in the Brahman (.53 kg/d, P > .15). There were significant dam breed effects on both percentage of milk fat and daily milk fat yield; Brahman exceeded Angus by .68% (P < .01) and 34.3 g/d (P < .01), respectively. There were significant forage effects for both percentage of milk fat and daily milk fat yield; common bermudagrass exceeded tall fescue by .5% (P < .01) and 62.3 g/d (P < .01), respectively. These data indicate that incorporation of Brahman germplasm into a grazing system that uses endophyte-infected fescue may be beneficial in daily milk yield but will probably not prevent decreases in milk fat production associated with grazing endophyte-infected tall fescue.

Relationship of thermal and chemical tolerance to transepithelial transport by cultured flounder renal epithelium

We tested the effects of mild heat shock (MHS) on tolerance of epithelial transport processes to a chemical inhibitor and, reciprocally, chemical stress effects on tolerance to severe thermal stress. Flounder renal tubules were cultured as monolayers on native collagen for 12 to 14 days at 22 degrees C and mounted in Ussing chambers in which transepithelial electrical characteristics and unidirectional [35S]sulfate fluxes were measured. 2,4-dichlorophenoxyacetic acid (0.5 mM) lowered net active sulfate secretion 25% (93.6 +/- 7.64-69.0 +/- 9.08 nmol/cm2/hr); MHS (27 degrees C for 6 hr followed by 1.5 hr at 22 degrees C) prevented this inhibition (92.4 +/- 5.72 nmol/cm2/hr) and stimulated transport 30% (125.7 +/- 11.06 nmol/cm2/hr). Cycloheximide or actinomycin D prevented the enhancing and protective effects of MHS. Preincubation in 100 microM ZnCl2 for 6 hr at 22 degrees C followed by 1.5 hr in zinc-free medium (mild zinc stress) enhanced net sulfate flux, protected transport from severe heat stress (32 degrees C for 1.5 hr followed by 1.5 hr at 22 degrees C) and prevented 2,4-dichlorophenoxyacetic acid inhibition in a manner similar to MHS. Mild zinc shock induced heat shock protein synthesis the same as MHS. Cycloheximide prevented the mild zinc shock effect on transport. The data show that thermal or chemical stressors can independently induce tolerance of transepithelial transport to both thermal and chemical insults and that stress-induced "protection" is due to enhancement of normal function rather than prevention of damage.

Functional recovery after reperfusion is predicated on recovery of myocardial oxidative metabolism

To test the hypothesis that recovery of myocardial oxidative metabolism (MVO2) is a necessary prerequisite for recovery of contractile function following reperfusion and to evaluate its dependency on the interval of antecedent ischemia before reflow, we evaluated 11 dogs serially for 4 weeks. Six dogs were subjected to prompt reperfusion (after 1 hour of coronary artery occlusion) and five were subjected to delayed reperfusion (after 4 hours of ischemia). Despite equivalent levels of myocardial blood flow with reperfusion, hearts subjected to prompt reperfusion had faster and more complete recovery of MVO2 (assessed by sequential positron emission tomography with [11C]acetate) and function (assessed by echocardiography) compared with dogs subjected to delayed reperfusion. Infarct size was diminished in dogs with prompt reperfusion. In all dogs, recovery of function with reperfusion was predicted and correlated with early recovery of MVO2 (r = 0.61, p < 0.04). The results demonstrate that prompt reperfusion is associated with more rapid and complete recovery of oxidative metabolism and function and support the hypothesis that the ability to metabolize substrate oxidatively is a necessary prerequisite for recovery of function.

Involvement of leukemia inhibitory factor and nerve growth factor in the development of dorsal root ganglion neurons

Leukemia inhibitory factor (LIF) was recently shown to stimulate the generation of sensory neurons from the murine neural crest in vitro. Here, we examine the respective activities of LIF and nerve growth factor (NGF) throughout the embryonic development of sensory neurons in dorsal root ganglia (DRG) and neural crest. In cultures of embryonic day 12 (E12) DRG, which contain sensory neuron precursor cells, a combination of both LIF and NGF are required for the differentiation of mature sensory neurons from their neurofilament negative (NF-) precursors. The primary differentiation step from NF- cell to NF+ immature neuron is promoted by LIF, whereas the survival and further maturation of the newly differentiated neurons depends on NGF. In cultures of sensory neurons isolated at the time of target innervation (E14 and E15 DRG), the survival of the majority of the neurons is dependent on NGF. However, LIF acts as a survival agent for a discrete population of NGF non-responsive neurons. From E16, the number of neurons maintained by LIF increases to &gt; 90% by birth. Consistent with the in vitro observations, LIF mRNA could be detected at early developmental stages (E12-E13), within the spinal column and DRG as well as the limbs and, later (after E15), in areas of sensory innervation (skin, limbs, feet and gut). This supports the idea that LIF, as well as NGF, may regulate sensory development in vivo.

Effects of cortisol on blood pressure and salt preference in normal humans

1. Adrenocorticotrophic hormone (ACTH) and corticosteroids stimulate salt appetite in laboratory animals. The hypothesis tested was that cortisol administration increases salt preference in humans. 2. Sodium taste studies (detection and recognition thresholds, taste intensity and preference tests) were conducted before, during and after cortisol administration (200 mg/day for 5 days) in normal men on a free diet. 3. Cortisol significantly increased systolic blood pressure (SBP), 113 +/- 3 - 130 +/- 4 mmHg, P < 0.05; diastolic blood pressure (DBP), 65 +/- 3 - 81 +/- 2 mmHg, P < 0.05; mean arterial pressure (MAP), 81 +/- 2 - 97 +/- 3 mmHg, P < 0.05; and bodyweight, 72.9 +/- 3.0 - 75.4 +/- 3.3 kg, P < 0.05. 4. Salt detection and recognition thresholds, taste intensity and preference for sodium chloride were unchanged following cortisol.

Genotype x environment interactions in preweaning traits of purebred and reciprocal cross Angus and Brahman calves on common bermudagrass and endophyte-infected tall fescue pastures

Preweaning data on 486 Angus, Brahman, and reciprocal cross calves (AB, BA) managed on common bermudagrass or endophyte-infected tall fescue were used to evaluate the interactions of forage type and sex of calf with direct effects, individual heterosis, and maternal effects. Calves were spring-born in 1988, 1989, 1990, and 1991 to five sires of each breed. Male calves were castrated at birth, and calves were not creep-fed. Average values of heterosis for birth weight, 205-d weight, weaning hip height, and weaning weight:height ratio (WT/HT) were important (P < .01) and consistent across forage environment. Heterosis for birth weight was larger in bull calves than in heifer calves (P < .05), whereas heterosis for other preweaning traits were consistent across sex of calf. Average maternal effects for WT/HT (P < .10) were important and consistent across forage environment. Maternal effects for birth weight were larger with bull calves than with heifer calves (P < .01). Maternal effects for weaning hip height favored the Angus dam managed on bermudagrass (P < .05) but not managed on fescue. A similar but nonsignificant trend occurred in maternal effects for 205-d weight. Direct effects for birth weight were larger in bull calves than in heifer calves (P < .01). Direct effects for weaning height were larger in calves managed on bermudagrass than in calves managed on tall fescue (P < .07). A similar but nonsignificant trend was evident in direct effects for 205-d weight. Direct effects for WT/HT were relatively small and unimportant.(ABSTRACT TRUNCATED AT 250 WORDS)

Measurement of blood pressure during pregnancy: evaluation of the 'TriCUFF'

Previous surveys have revealed that a major source of error in measuring blood pressure in pregnant women is failure to use a large cuff when necessary. We have tested the hypothesis that this problem could be overcome by using a single cuff containing automatically selected inflation bladders of appropriate size, the TriCUFF. We compared readings obtained with the TriCUFF with those obtained using standard adult or large (obese) cuffs in 51 pregnant women. Thirty nine had normal upper arm circumferences (< 34 cm) and 12 increased arm circumferences (> or = 34 cm). The TriCUFF overestimated standard cuff systolic and diastolic (phase IV) readings by 2 (0-4) mmHg (mean, 95% confidence limits) (p < 0.05). There was no difference between readings for women with large arms. Agreement between readings by both methods was acceptable for clinical practice in most cases. Use of the TriCUFF could significantly improve the accuracy of blood pressure recording in pregnant women.

Structure and expression of the GM-CSF receptor alpha and beta chain genes in human leukemia

In this paper we report on the structure and expression of the genes encoding the alpha and beta chains of the granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor in human leukemia. The alpha chain gene is highly polymorphic in normal individuals and no evidence for rearrangement within this locus was found in 47 hemopoietic, nine non-hemopoietic malignancies and five human cell lines. Using the polymerase chain reaction the gene for the alpha chain was shown to be expressed in 18/18 primary myeloid as well as 8/8 primary lymphoid leukemias analysed. To investigate the integrity of the mRNA, polymerase chain reactions (PCR) using a combination of oligonucleotides spanning the entire coding region of the alpha chain were performed. Normal sized fragments were generated with all combinations of oligonucleotides from all but one leukemia. One chronic lymphoid leukemia displayed an apparent alteration at the 3' end of the 3' untranslated region of the alpha chain mRNA. No polymorphisms were detected in the beta chain gene which was also not rearranged in any of the samples analysed. The beta chain mRNA was expressed in 17/18 primary myeloid and 7/8 primary lymphoid leukemias and in those leukemias there was no evidence for any lesions in the mRNA, as judged by PCR fragment size. Thus gross structural lesions in the genes encoding the GM-CSF receptor alpha and beta chains appear to be infrequent in hemopoietic neoplasms.

Family coping and premenstrual symptomatology

OBJECTIVE

To examine how families cope when the woman experiences premenstrual symptomatology.

DESIGN

A descriptive panel design and purposive, nonprobability sampling through interviews and questionnaires.

SETTING

Participants' homes.

PARTICIPANTS

One hundred four couples who met the study criteria were recruited from medical practices and community seminars and through media announcements.

MEASURES

Study outcome measures were formulated after data collection.

RESULTS

High-symptom families used spiritual coping strategies more frequently than low-symptom families (R = .427, p = 0.003 in women, p < 0.001 in men). Husbands were more likely than wives to report that their families coped by believing that the problem would go away if they waited long enough (t = -3.06, p = 0.003). Husbands of women with high symptomatology reported that their families used this passive approach to a significant degree (t = -3.43, p = 0.001).

CONCLUSIONS

Religious or spiritual support may be especially important to families in which the woman suffers from premenstrual symptomatology. These families may also keep problems within the family and be socially detached. Nurses may help by encouraging the use of social supports, religious or spiritual support, and other family resources.

Aerosolized lipopolysaccharide increases pulmonary clearance of 99mTc-DTPA in rabbits

Bacterial endotoxins alter the permeability of endothelium, but little is known of their effect on epithelium. We exposed specific pathogen-free rabbits to aerosolized Pseudomonas aeruginosa LPS or saline and performed serial measurements of RL, Cdyn, BP, WBC count and differential, and platelet counts. Pulmonary 99mTc-DTPA half-life was measured 4, 6, or 8 h after exposure. The animals were sacrificed and BAL performed. Background and PMA-stimulated superoxide production was measured from individual AM using electrooptical determination of reduction of NBT. Lung tissue was processed for light microscopy and ratio of wet to dry weight. 99mTc-DTPA half-life was significantly shorter in LPS-exposed animals at 6 h (p < 0.05) and 8 h (p < 0.001). There were no differences in Cdyn, RL, BP, WBC, differential, platelet, or BAL cell count at any time between groups. No histologic changes or differences in lung wet to dry weight ratios were found. PMA-stimulated AM superoxide production was significantly increased (p < 0.01) in LPS-exposed animals. This effect was time dependent and could be duplicated in AM from control animals following a 4-h incubation with LPS, lavage fluid from LPS-exposed animals, or recombinant murine TNF. These results demonstrate that aerosolized Pseudomonas LPS increases pulmonary epithelial permeability and primes AM superoxide production.

Structure-activity relationship of a series of sensory irritants

The relative potencies for a series of sensory irritants, with structures based on toluene, were determined by measuring the airborne concentrations that caused a 50% decrease in respiratory rate in Swiss-Webster mice. This concentration is referred to as the RD50. Toluene, a relatively nonirritating compound, and compounds with chlorine, two chlorines, bromine, and iodine atoms substituted on the alpha carbon of toluene were tested. The RD50s for these compound types were determined to be 4900, 27, 27, 5.2, and 4.3 ppm, respectively. In addition, compounds with chlorine substituted at the ortho, meta, and para positions on the toluene ring were also tested. The RD50s were determined to be 4.9, 13, and 14 ppm, respectively. The structure-activity relationships of the compounds studied are explained by a model (Abraham et al., 1990; Nielsen and Alarie, 1982) that relates the interaction of sensory irritants with a receptor protein in a lipid bilayer. The trends in the RD50s, and thus sensory irritation, for the compounds studies are related to the development of a partial positive charge on the toluene alpha carbon by the positioning of a ring chlorine and the bond dissociation energies of the alpha carbon-halogen bond for the iodo, bromo, and chloro isomers of benzyl halide.

A DNase I-hypersensitive site in the second intron of the murine IL-4 gene defines a mast cell-specific enhancer

IL-4 is a potent immunoregulatory cytokine that exhibits extremely diverse effects on a number of target cells. Although IL-4 was originally described as a T cell-derived product, it is evident that cells of the basophil/mast cell lineage are also an important source of this cytokine. Based on their different tissue distribution, mast cell and T cell-derived IL-4 may have distinct effects on local immune responses. The physiologic production of IL-4 appears to be tightly regulated because most T and mast cells require activation to express significant levels of IL-4. In contrast, a majority of murine transformed mast cell lines constitutively express relatively high levels of IL-4. In this study, transformed mast cell lines were used as models to define cis acting sequences that regulate mast cell IL-4 transcription. Chloramphenicol acetyltransferase reporter gene constructs containing 6.3 kb of 5' IL-4 flanking sequence direct relatively low chloramphenicol acetyltransferase expression in these cells. These results indicated that additional sequences may be important in stimulating transcriptional activity of the IL-4 gene. Using DNAse I hypersensitive site analysis to define other potential IL-4 transcriptional regulatory regions, two sites were identified in the murine IL-4 gene that appear to be unique to IL-4 expressing transformed mast cells. One site defines an intronic sequence that exhibits prototypic enhancer activity in several independently derived transformed mast cell lines. This enhancer is also active in stimulated, non-transformed mast cells but not stimulated EL-4 T cells. Taken together, these data indicate that the IL-4 intronic sequence contains a mast cell specific enhancer that plays an essential role in the unregulated expression of IL-4 in transformed mast cells and may also be important in the inducible expression of IL-4 in normal mast cells.

A DNase I-hypersensitive site in the second intron of the murine IL-4 gene defines a mast cell-specific enhancer

IL-4 is a potent immunoregulatory cytokine that exhibits extremely diverse effects on a number of target cells. Although IL-4 was originally described as a T cell-derived product, it is evident that cells of the basophil/mast cell lineage are also an important source of this cytokine. Based on their different tissue distribution, mast cell and T cell-derived IL-4 may have distinct effects on local immune responses. The physiologic production of IL-4 appears to be tightly regulated because most T and mast cells require activation to express significant levels of IL-4. In contrast, a majority of murine transformed mast cell lines constitutively express relatively high levels of IL-4. In this study, transformed mast cell lines were used as models to define cis acting sequences that regulate mast cell IL-4 transcription. Chloramphenicol acetyltransferase reporter gene constructs containing 6.3 kb of 5' IL-4 flanking sequence direct relatively low chloramphenicol acetyltransferase expression in these cells. These results indicated that additional sequences may be important in stimulating transcriptional activity of the IL-4 gene. Using DNAse I hypersensitive site analysis to define other potential IL-4 transcriptional regulatory regions, two sites were identified in the murine IL-4 gene that appear to be unique to IL-4 expressing transformed mast cells. One site defines an intronic sequence that exhibits prototypic enhancer activity in several independently derived transformed mast cell lines. This enhancer is also active in stimulated, non-transformed mast cells but not stimulated EL-4 T cells. Taken together, these data indicate that the IL-4 intronic sequence contains a mast cell specific enhancer that plays an essential role in the unregulated expression of IL-4 in transformed mast cells and may also be important in the inducible expression of IL-4 in normal mast cells.

The kidney in hypertensive pregnancies--victim and villain

Many changes in renal function occur in normal pregnancy. Without a proper understanding of these changes, routine clinical investigations may easily be misinterpreted. Women with preeclampsia have further alterations in renal function and, in occasional cases, develop acute renal failure. Understanding of abnormal renal physiology and hormonal changes in these women allows the clinician to interpret biochemical tests appropriately and make proper use of vasodilator therapy with careful attention to volume homeostasis. Women who undertake pregnancy with a primary renal disease, most commonly glomerulonephritis or reflux nephropathy, have a higher risk of adverse fetal and maternal outcomes. Awareness of these risks provides a basis for proper preconceptual counseling, as well as careful monitoring of maternal blood pressure and renal function and fetal growth during such pregnancies. These strategies will optimize the chances of a successful pregnancy outcome for both mother and baby.

Atrial natriuretic peptide in pregnancy: response to oral sodium supplementation

1. The control of extracellular fluid volume (ECFV) in normal pregnancy may be related to changes in atrial natriuretic peptide. Previous studies in non-pregnant subjects have suggested that plasma atrial natriuretic peptide (ANP) increases in response to dietary sodium supplementation because of an increase in plasma volume, although this has not been measured directly. 2. Nine women who were pregnant in the third trimester undertook oral sodium supplementation (136 mmol) for 5 days in addition to their usual diet. Twenty-four hour urinary sodium excretion increased by 125 +/- 54 mmol/day (mean +/- s.d.; P less than 0.01). Plasma volume was unchanged, although total ECFV tended to increase (P less than 0.09 and bodyweight increased (1.3 +/- 1.4 kg; P less than 0.01) at the end of these diets. 3. Plasma ANP increased by 30.7 [8.6, 34.5] pmol/L (median [25th, 75th percentile]; P less than 0.05), while plasma renin concentration decreased significantly from 7.3 [6.2, 11.2] to 2.6 [1.7, 3.9] pmol angiotensin I/mL (P less than 0.01), as did plasma aldosterone concentration (1435 [1162, 1722] to 753 [595, 1110] fmol/mL; P less than 0.01). Plasma vasoactive intestinal peptide was unchanged. 4. Pregnant women respond to increased dietary sodium with an increase in plasma ANP in the absence of a significant increase in plasma volume. The acute regulation of plasma ANP in response to increases in dietary sodium in pregnant women does not appear to be mediated by changes in intravascular fluid volume.

Acute and chronic regulation of atrial natriuretic peptide in human pregnancy: a longitudinal study

OBJECTIVE

To determine whether the increase in extracellular fluid volume (ECFV) that occurs during pregnancy alters: (1) the baseline regulation of atrial natriuretic peptide (ANP); or (2) the ANP response to intravascular volume expansion with either haemaccel or hypertonic saline.

DESIGN

A group of normal pregnant subjects was studied longitudinally on three occasions, commencing before 16 weeks of gestation. They were compared with a group of age-matched non-pregnant women. Dietary sodium intake and posture were carefully controlled.

METHODS

Plasma volume and total ECFV were determined by tracer dilution methods, using Evans Blue and 20% mannitol, respectively. Plasma ANP and aldosterone concentrations were measured by radioimmunoassay.

RESULTS

Plasma ANP did not increase during pregnancy despite increases in both plasma and total ECFV. The plasma ANP response to acute intravenous volume expansion in later pregnancy appears to be more sensitive than either in early pregnancy or in non-pregnant subjects. The initial ANP response to infusions of haemaccel during pregnancy was greater than the ANP response to saline.

CONCLUSIONS

During a normal pregnancy, plasma ANP is maintained in the normal non-pregnant range, despite an increase in plasma volume when the effects of dietary sodium intake and posture are carefully accounted for. The ANP response to intravenous volume expansion is enhanced in late pregnancy. The greater ANP response to haemaccel infusions during pregnancy suggests that an increase in atrial stretch mediates the secretion of ANP following intravenous volume expansion.

Measurement of plasma volume in pregnancy

1. Determination of the plasma volume in pregnant women is a useful research tool and may become an important clinical measurement. We used three methods to determine plasma volume using Evans Blue dye: (1) the 'usual' method, measuring serum absorbance at a wavelength of 610 nm, (2) a two-wavelength method, and (3) precipitation of non-albumin proteins by the addition of polyethyleneglycol before measuring serum absorbance at a wave-length of 620 nm. These were each compared with the standard 125I-human serum albumin method in 20 non-pregnant subjects. Subsequently, the polyethylene glycol method was considered the standard and the three Evans Blue dye methods were compared in 20 pregnant women. 2. In non-pregnant subjects mean plasma volumes did not differ significantly according to the method used. However, the limits of agreement with 125I-human serum albumin method were closest for the polyethyleneglycol method, for both clear and turbid sera. 3. In pregnant women, mean plasma volume values did not differ according to the Evans Blue dye method used, but the limits of agreement were significantly closer with the two-wavelength method than with the 'usual' method (P less than 0.05) largely owing to the effects of turbid sera. 4. These studies demonstrate that considerable error may occur when the Evans Blue dye concentration is determined in turbid sera by the 'usual' method. This can be overcome by the use of the two-wavelength method or the polyethyleneglycol method. The most accurate results will be obtained if the latter method is employed routinely to determine plasma volume in pregnant women.

Renin-aldosterone relationships in pregnancy-induced hypertension

The relationship between plasma renin (PRC) and aldosterone (PAC) concentrations was determined in 83 normal third trimester pregnant women (P), 50 women with pregnancy-induced hypertension (PIH), and 80 age-matched nonpregnant women not taking oral contraceptives (NP). Normal pregnant women had a slightly higher 24-h urine sodium: creatinine ratio than the other groups (P less than .001) (NP: 10 +/- 4 v P: 15 +/- 8 v PIH: 12 +/- 7; mean +/- SD). Both PRC and PAC were higher in normal pregnant women as was the ratio PAC:PRC [normal pregnant 195 (158 to 337) v nonpregnant 130 (101 to 209), median (interquartile range); P less than .001]. This was accompanied by a slightly reduced slope (sensitivity) of the logPRC-logPAC relationship in normal pregnant women (P less than .05). Women with PIH had reduced PRC and PAC compared with normal pregnant women but a two-fold greater increase in PAC:PRC ratio [PIH 411 (277 to 598) v normal pregnancy 195 (158 to 337), P less than .001], with a rise in the slope (sensitivity) of the logPRC-logPAC relationship in women with PIH (P less than .001). Thus there is proportionately greater aldosterone release in the third trimester of normal pregnancy than in nonpregnant women. This preferential increase in aldosterone may be due to altered adrenal sensitivity to angiotensin II or may reflect enhanced nonangiotensin stimulation of aldosterone during pregnancy. Women with PIH have reduced PRC and PAC but relatively greater stimulation of aldosterone than normal pregnant women, possibly due to enhanced sensitivity of the adrenal glands to angiotensin II.

Serum amylase activity and calcium and magnesium concentrations in young cattle grazing fescue and Bermuda grass pastures

The study reported here was part of a long-term investigation of the effects of genotype on growth, reproduction, and metabolism in cattle grazing common Bermuda grass and endophyte-infected fescue pastures. In June 1990, blood samples were collected from the tail vein of yearling heifers and steers (Angus [AA], Brahman [BB], and their reciprocal crosses [AB, BA], n = 97). Serum amylase activity was assayed enzymatically; serum Ca and Mg concentrations were determined by atomic absorption spectrophotometry. The effects of endophyte-infected fescue depended on genotype (P less than 0.001). In yearlings having at least 1 Angus parent (AA, AB, BA), grazing endophyte-infected fescue was associated with higher serum amylase activity than was grazing Bermuda grass. But serum amylase activities of BB yearlings consuming either forage were similar. Moreover, for either forage, substantial differences were related to genotype (P less than 0.007) and gender (P less than 0.05). Angus yearlings had higher serum amylase activity than did Brahman yearlings; AB and BA yearlings had intermediate values. Heifers had higher amylase activity than did steers. The relationship among serum values of amylase, Ca, and Mg depended on forage. Yearlings consuming endophyte-infected fescue and having at least 1 Angus parent had a moderate negative correlation between serum amylase activity and Ca concentration (r = -0.53; P less than 0.0005); that is, in calves of genotypes with increased amylase activity while consuming endophyte-infected fescue (AA, AB, BA), the higher the amylase activity, the lower the serum Ca concentration. However, in yearlings consuming Bermuda grass, serum amylase and Ca values were not correlated.(ABSTRACT TRUNCATED AT 250 WORDS)

Thermoprotection of a functional epithelium: heat stress effects on transepithelial transport by flounder renal tubule in primary monolayer culture

Primary monolayer cultures of winter flounder renal proximal-tubule cells were used to determine whether transepithelial transport could be protected from the damaging effects of extreme temperature by previous mild heat shock. Renal tubule epithelial cells were enzymatically dispersed and reorganized as confluent monolayer sheets on native rat tail collagen. Transepithelial electrical properties (potential difference, resistance, short-circuit current, and Na(+)-dependent glucose current) and unidirectional [35S]sulfate fluxes were measured in Ussing chambers at 22 degrees C. Examination of transepithelial electrical properties following acute 1-hr elevation of temperature over a range of 22-37 degrees C provided the basis for the "mild" versus "severe" thermal stress protocols. Severe elevation from 22 degrees C to 32 degrees C for 1.5 hr followed by 1.5 hr at 22 degrees C significantly decreased glucose current (7 +/- 0.7 to 3 +/- 0.8 microA/cm2) as well as net sulfate secretion [131 +/- 11 to 33 +/- 11 nmol/(cm2.hr)]. Mild heat shock of 27 degrees C for 6 hr prior to this severe heat shock completely protected both glucose transport (6 +/- 0.7 microA/cm2) and sulfate flux (149 +/- 13 nmol/(cm2.hr)]. Scanning electron microscopy showed that the number of microvilli on the apical (luminal) surface of the epithelium was decreased after a 32 degrees C heat shock. Monolayers exposed to 27 degrees C for 6 hr prior to incubation at 32 degrees C showed no loss of microvilli. SDS/PAGE analysis of protein patterns from the cultures showed that three classes of heat shock proteins were maximally induced at 27 degrees C. Inhibition of protein synthesis by cycloheximide prevented the thermoprotective effect of mild heat shock. This suggests that certain renal transport functions can be protected from sublethal but debilitating thermal stress by prior mild heat shock and that heat shock proteins may play a role in this protection.

Endothelium-derived prostacyclin: effect of serum from women with normal and hypertensive pregnancy

1. Pregnancy-induced hypertension (or pre-eclampsia) is characterized by vasoconstriction, platelet aggregation and altered capillary permeability, implying disordered endothelial function and/or structure. Serum from women with pregnancy-induced hypertension has been reported by others to be cytotoxic to endothelial cells in vitro. We hypothesized that such serum contains a factor that limits the ability of endothelial cells to produce and/or release prostacyclin. 2. Prostacyclin production by intact and damaged cultured human umbilical vein endothelial cells was measured after incubating these cells with serum from non-pregnant and normal pregnant women and women with pregnancy-induced hypertension. Confluent human umbilical vein endothelial cell monolayers (intact and damaged) were incubated with sera for 24 h at 37 degrees C followed by 1 h of incubation with added thrombin (stimulated production) or media (basal production). Supernatants were then collected for measurement of 6-keto-prostaglandin F1 alpha by radioimmunoassay. 3. Basal production of 6-keto-prostaglandin F1 alpha was greater in response to serum from non-pregnant women than to that from pregnant women. Within each group, sub-lethally damaged cells had a similar basal production of 6-keto-prostaglandin F1 alpha to that of intact cells. 4. Basal production of 6-keto-prostaglandin F1 alpha by intact or damaged cells incubated with sera from normal pregnant women and from women with pregnancy-induced hypertension was similar. 5. In all groups the addition of thrombin to intact endothelial cells increased 6-keto-prostaglandin F1 alpha production approximately 15-30-fold over basal levels, but only three- to five-fold in damaged endothelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Diversity of blood pressure recording during pregnancy: implications for the hypertensive disorders

OBJECTIVE

To determine the number and type of methods used to measure blood pressure (BP) in pregnant women.

DESIGN

Questionnaires were distributed to obstetricians and midwives concerning: method of recording BP (arm used, subject position, Korotkoff sounds recorded); accuracy of recording BP (cuff size, sphygmomanometer calibration); and definitions of hypertension in pregnancy.

PARTICIPANTS

Obstetricians (academic, staff and private) in Sydney; members of the New South Wales Midwives' Association.

MAIN RESULTS

Responses were received from 85 obstetricians (55% of those surveyed) and 173 midwives (43%); the overall response rate was 46%. Almost 80% of respondents agreed that diastolic BP above 90 mmHg constituted hypertension during pregnancy but at least six different methods were used to obtain BP readings, with a potentially large variability in the BP so obtained. Forty-five per cent of obstetricians and 72% of midwives stated that they always used a large cuff when necessary. Few had had their sphygmomanometer calibrated within the previous two years.

CONCLUSIONS

There is considerable variability in the way BP is recorded in pregnant women. Hypertension in pregnancy may therefore be over or under diagnosed according to the method employed and there is an urgent need for international consensus on how to measure BP accurately in pregnancy.

Going public as an AIDS family caregiver

Images of AIDS invoke fears of contagion, disability and formidable death, and moral overtones directed toward drug use, sexuality and sexual identity and freedom. Responses to these images are both private and public, and have profound consequences for individuals whose lives have been touched by the disease, both the person with AIDS and the family caregiver. The purpose of this paper is to analyze in detail 'going public,' one category of a substantive theory of AIDS family caregiving. This category was developed from a grounded theory study of 53 AIDS family members who were asked to describe their experiences as an AIDS family caregiver during an indepth interview. Data were content analyzed using constant comparative analysis. Going public referred to how AIDS family caregivers let others known that they were caring for a PWA. Specifically, going public entailed selecting appropriate persons and audiences to tell, formulating approaches to communicating information, and considering the risks and benefits of the possible choices. The description of going public as an AIDS family caregiver details the assertiveness involved in political action and social change, contrasted with the isolation and secrecy involved in maintaining relationships with others under the condition of a stigmatizing illness. Data revealed a particular emphasis on the phenomenon of 'guilt by association'. Because of their close relationship to a person with AIDS, caregivers were obligated to share the stigma of AIDS and were likewise discredited. Findings from our study emphasize the tremendous personal suffering experienced by caregivers which was associated with AIDS stigma in the form of rejection, loss of friends and harassment. Data also revealed the strong commitment of many caregivers to social activism which ranged from participating in educational efforts to marching in demonstrations. The rationale for the apparent increased activism among AIDS family caregivers compared to other groups of caregivers is explored. Going public highlights both the personal suffering and social manifestations of AIDS, significant issues to consider in planning health services for the second decade of the AIDS epidemic.

Haemodynamic and metabolic effects of short term administration of synthetic sex steroids in humans

Synthetic sex steroid administration is a major cause of iatrogenic hypertension but little is known of the haemodynamic or metabolic consequences of these steroids. This study examined the short term blood pressure, volume and metabolic consequences of 5 day administration of synthetic androgen to normal men and synthetic oestrogen or progestogen to normal women. Healthy subjects (8 women, 6 men) on a constant diet took part in each of 3 studies. Males received testosterone undecanoate 120 mg/day (n = 6) and females either ethinyloestradiol 0.3 mg/day (n = 5) or norethisterone 15 mg/day (n = 6) for 5 days in the last week of the cycle. Norethisterone increased lying (+7 mmHg) and standing (+8 mmHg) systolic pressure but the other steroids did not alter blood pressure. All 3 treatments increased body weight. There were no consistent changes in plasma electrolytes or glucose with any steroid, and no urinary sodium retention or changes in urine Na:K ratio. Haematocrit fell on ethinyloestradiol but no steroid significantly increased plasma volume (measured as volume of distribution of 125I human serum albumin). Renin substrate and cortisol rose and renin concentration fell on ethinyloestradiol. These studies suggest that the progestogen component may contribute to the blood pressure raising effects of oral contraceptives.

Extracellular fluid volumes in pregnancy-induced hypertension

OBJECTIVES

Reduction in plasma volume (Pvol) of women with pregnancy-induced hypertension (PIH; preeclampsia) has both physiological and clinical implications. This study was undertaken to determine the following variables in women with PIH: (1) the incidence of reduced Pvol; (2) the distribution of total extracellular fluid volume (ECFV); (3) the relationship between Pvol and birth weight; and (4) whether any readily available clinical or laboratory parameters predict the presence of reduced Pvol.

SETTING

Teaching hospital obstetric unit and antenatal clinic.

PARTICIPANTS

Forty-nine primigravidae with PIH (28 mild, 21 severe), 54 normotensive primigravidae and 25 non-pregnant controls.

DESIGN

Pvol was measured using Evans Blue dye and ECFV as the mannitol space. These measures were compared amongst groups, and also within groups for those with PIH, according to the severity of their disorder and the presence of proteinuria or oedema. Blood pressure, haematocrit, uric acid and serum albumin were also evaluated as predictive indices of reduced Pvol in women with PIH.

RESULTS

Pvol, ECFV and the Pvol:ECFV ratio all increased during normal pregnancy. Pvol in women with PIH was reduced compared with normal pregnancy and correlated significantly with birth weight. Total ECFV was unchanged in women with PIH, but their Pvol:ECFV ratio was significantly reduced compared with normal pregnancy. Although there was a significant correlation between Pvol and haematocrit in women with PIH, haematocrit was a poor predictor for reduced Pvol. Diastolic blood pressure greater than 100 mmHg, persistent proteinuria and severe PIH were the only reliable positive predictors of a reduced Pvol.

CONCLUSIONS

Pvol is related to birth weight, but is reduced in only approximately half of women with PIH. This reduced Pvol is the result of maldistribution, not loss, of total ECFV, and can be predicted by high diastolic blood pressure, proteinuria or other clinical signs of severity, but not by haematocrit.

Inhibition of differentiation in a murine F9 embryonal carcinoma cell subline by leukemia inhibitory factor (LIF)

Leukemia inhibitory factor (LIF) is a cytokine previously shown to maintain pluripotent embryonic stem cells in their undifferentiated state. We have examined the effects of LIF in nullipotent embryonal carcinoma cell lines, and have found that LIF blocks differentiation induced by retinoic acid and at low temperature in OTF9 cells. LIF did not block differentiation in a parent F9 cell line. For OTF9 cells, LIF acts early in differentiation, inhibiting the appearance of parietal endoderm-type product cells. However, it acts subsequent to retinoic acid, and at least one early retinoic acid-induced event is unaltered in the presence of LIF. This finding provides both a means of dissecting the cascade of events leading to EC cell differentiation, and a well-characterised target cell type for studying the mechanism of action of LIF.

Nutritional patterns of centenarians

This study compares the dietary patterns of centenarians (n = 24) with elderly adults in their sixties (n = 54) and eighties (n = 47). Compared to the younger cohorts, centenarians consumed breakfast more regularly, avoided weight loss diets and large fluctuations in body weight, consumed slightly more vegetables, and relied on their doctor and family more than on the news media for nutrition information. On the other hand, centenarians were less likely to consume diets low in fat and to comply with nutritional guidelines designed to reduce the risk of chronic disease. Elderly black men consumed diets higher in sweets and fat compared to black women and white men and women. Nearly three times as many blacks expressed the desire to eat more nutritiously. High nutrition risks, particularly in blacks, were associated with lower physical and mental health and impaired activities of daily living.

Atrial natriuretic peptide and plasma volume in pregnancy-induced hypertension

Pregnancy-induced hypertension (PIH) is characterized by a relative decrease in plasma volume and renin and aldosterone concentrations as well as increased capillary permeability compared with normal pregnancy. As many of these features could be explained by the actions of atrial natriuretic peptide (ANP), we examined the relationship between plasma volume and plasma ANP in women with PIH and in normal third trimester pregnant women, and whether ANP responses to alterations in posture were intact in women with PIH. Basal plasma ANP measured after 20 min lateral recumbency in women with PIH was 24.0 (13.9, 33.1) pmol/L (median [25th, 75th percentile]), which was significantly greater than in normal pregnant women (9.9 [6.3, 16.0]), (P less than .05). Plasma ANP did not differ between those with and without proteinuria in the PIH group. Plasma volume was decreased in women with PIH (20.1 [19.0, 23.2] mL/cm) v 23.5 [21.4, 25.3], P less than .05). Plasma renin concentration but not plasma aldosterone concentration was also decreased significantly in women with PIH compared with normal pregnant women (P less than .001) and both were correlated negatively with plasma ANP. Following prolonged lateral recumbency, plasma ANP rose to 26.9 [19.1, 44.1] pmol/L in women with PIH (P less than .05), which was still significantly greater than in normal pregnant women (15.5 [6.7, 21.9] pmol/L) (P less than .05). In a subgroup of these subjects, 30 min head-up tilt decreased plasma ANP by 5.2 [0.9, 22.3] pmol/L in women with PIH and by 6.1 [2.2, 10.3] pmol/L in normal pregnant women, a nonsignificant difference.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS family caregiving: transitions through uncertainty

The purpose of this study was to describe the experience of AIDS family caregiving. Grounded theory provided the methodological basis for qualitative data generation and analysis. Extensive interviews were conducted with 53 individuals (lovers, spouses, parents of either adults or children with AIDS, siblings, and friends) who were taking care of a person with AIDS at home. Relevant features of the social context of AIDS family caregiving were explored. Findings revealed the basic social psychological problem of Uncertainty, a core category of Transitions Through Uncertainty, and five subcategories: Managing and Being Managed by the Illness; Living With Loss and Dying; Renegotiating the Relationship; Going Public; and Containing the Spread of HIV. Stages and strategies of each subcategory detailed individuals' responses to the challenges of AIDS family caregiving and elaborated the day-to-day experiences. Uncertainty as a critical challenge for individuals and families facing life-threatening illness is discussed in light of recent research.

Comparison of outcomes for clients seeking and assigned to supported housing services

As part of state-supported interventions to reduce risk of rehospitalization, seriously disabled psychiatric patients who had been involuntarily hospitalized twice in the previous three years were assigned to receive supported housing services in an Oregon community. Compared with 22 voluntary clients in the same supported housing program, the 21 involuntary (assigned) clients rated higher on risk factors such as history of suicide attempts, self-neglect, homelessness, and medication noncompliance, The involuntary clients showed a much higher utilization of supported housing services and case management, psychiatric, and shelter services during the nine months after entry into the program, and they had a higher one-year rehospitalization rate. However, they used substantially fewer inpatient days in the six months after entry in the program than in the six months before.

Pancytopenia after accidental overdose of methotrexate. A complication of low-dose therapy for rheumatoid arthritis

OBJECTIVE

Pancytopenia is an unusual complication of low-dose methotrexate therapy in rheumatoid arthritis. We report a near fatal case that followed an accidental overdose.

CLINICAL FEATURES

An 80-year-old Caucasian woman with rheumatoid arthritis presented with pancytopenia and severe mucositis. She had taken her weekly methotrexate dose on four sequential days, due to an error in filling a "Dosette" box.

INTERVENTION AND OUTCOME

Following treatment with piperacillin, gentamicin and folinic acid, she recovered completely.

CONCLUSIONS

Low-dose methotrexate therapy is uncommonly associated with haematological toxicity. This generally occurs in patients with known risk factors for such reactions. Patient reliability should be considered if methotrexate therapy is contemplated.

Nematodes associated with blackberry in arkansas

A survey of the nematodes in blackberry (Rubus sp.) rhizospheres was conducted in Arkansas from 1986 to 1989. The state was divided arbitrarily into four quadrants. A total of 134 soil samples was collected, and 150-cm 3 subsamples were assayed for nematodes. Twenty-one species of plant-parasitic nematodes in 11 genera were extracted from the samples. There were differences (P = 0.05) among quadrants of the state in percentage occurrence of the nematodes and in population densities in samples. Xiphinema americanum, Helicotylenchus spp. (H. paraplatyurus, H. platyurus, and H. pseudorobustus), and Pratylenchus spp. (P. vulnus and P. zeae) were found in all quadrants. Xiphinema americanum population density was near 1,000 per 150 cm(3) soil in soil samples from two locations. Other nematodes found in one or more quadrants were Criconemella spp. (C. axeste, C. curvata, C. denoudeni, C. ornata, C. sphaerocephala, and C. xenoplax), Paratrichodorus minor, Tylenchorhynchus claytoni, Hirschmanniella oryzae, Hoplolaimus magnistylus, Scutellonema bradys, and undescribed species of Criconema, Tylenchulus, Xiphinema, and Meloidogyne. Criconemella sphaerocephala and Helicotylenchus platyurus are reported from Arkansas for the first time. Helicotylenchus paraplatyurus is reported from the United States for the first time.

Endothelin: a potent stimulator of intestinal ion secretion in vitro

Effects of endothelin (ET) on electrical properties and Na+ and Cl- fluxes in stripped rabbit ileal mucosa were investigated in vitro in Ussing chambers. Results demonstrate that serosal addition of ET-1, ET-2, ET-3 or the precursor 38 amino acid 'big endothelin' produce dose-dependent increases in short-circuit current (Isc) with maximal effects at approx. 100 nM, 100 nM, 10 nM and 100 nM, respectively and half-maximal effects at 1.4 nM, 5 nM, 1.4 nM and 20 nM, respectively. Mucosal addition of ET-3 failed to elicit a response. Changes in Isc elicited by ET-3 are accompanied by decreases in net fluxes of both Na+ and Cl-. The cyclooxygenase inhibitors, indomethacin and piroxicam, inhibited the increase in Isc produced by ET-3 and indomethacin also abolished the changes in Na+ and Cl- fluxes produced by ET-3. However, no changes in the release of PGE2, thromboxane B2 or 6-keto-prostaglandin F1 alpha could be detected up to 20 min after the addition of ET-3. Preincubation of tissues with neuronal agonists or antagonists, antihistamines or an LTD4/LTE4 receptor antagonist, SKF 104353, failed to alter the response to ET-3. Furthermore, removal of serosal Ca2+ also failed to inhibit the change in Isc produced by ET-3. These results indicate that endothelin is a potent intestinal secretagogue which does not appear to elicit its response through stimulation of PGE2, thromboxane A2 or prostacyclin.

Regulation of atrial natriuretic peptide release in pregnancy: responses to posture

The response of plasma atrial natriuretic peptide to three changes in posture that alter atrial stretch was examined in the late phase of pregnancy: (1) after 20 minutes in lateral recumbency, remaining upright for 2 hours decreased median plasma atrial natriuretic peptide values from 37.8 (25th percentile, 22.9 and 75th percentile; 64.2) to 21.8 (10.1 and 28.4) pg/ml in pregnant women (p less than 0.05) and from 39.2 (27.8 and 51.2) to 24.0 (18.9 and 35.4) pg/ml (p less than 0.001) in age-matched nonpregnant women; (2) prolongation of lateral recumbency from 20 to 80 minutes increased median plasma atrial natriuretic peptide levels from 31.9 (25.6 and 37.3) to 47.8 (33.0 and 74.6) pg/ml in pregnant women (p less than 0.001) and from 36.5 (22 and 58.6) to 54.0 (36.3 and 111.7) pg/ml in nonpregnant women (p less than 0.01); (3) adoption of supine posture during the late phase of normal pregnancy did not alter median plasma atrial natriuretic peptide values significantly [30.4 (26.7 and 42.5) pg/ml during lateral recumbency compared with 34.2 (25.4 and 43.5) pg/ml while supine]. Plasma atrial natriuretic peptide values fell after supine posture in only half the women and supine hypotension occurred in one subject. These studies demonstrate that upright and prolonged lateral recumbent postures significantly influence plasma atrial natriuretic peptide values during pregnancy, as they do in the nonpregnant state, but that supine posture does not alter plasma atrial natriuretic peptide values significantly. Posture must be carefully accounted for in any study of plasma atrial natriuretic peptide in pregnancy.

Alternatively spliced RNAs encode several isoforms of CD46 (MCP), a regulator of complement activation

Five alternative cDNA clones were isolated for CD46, also known as the membrane cofactor protein (MCP) for the factor I-mediated cleavage of the complement convertases. One of these cDNA clones (a) was identical to an earlier MCP clone. The other four CD46 clones contained the four NH2-terminal short consensus repeat (SCR) units of MCP, but differed at the region encoding the carboxyl-terminal of the protein which includes an extracellular segment rich in Ser, Thr, and Pro residues, a hydrophobic membrane-spanning domain, and a 33 amino acid cytoplasmic tail. The different CD46 cDNAs have variously: (b) inserted a 93 base pair (bp) exon resulting in a new cytoplasmic tail of 26 amino acids; (c) deleted a 42 bp exon from the extracellular Ser/Thr rich region: (d) used a cryptic splice acceptor sequence to delete 37 bp from an exon encoding transmembrane sequence; or (e) failed to splice the intron after the four SCR units. These were shown by northern blot and polymerase chain reaction to arise by alternative splicing of CD46 RNA. Forms (a), (b), and (c) of CD46 RNA are common in placental RNA, but (d) was rare, and (e) was incompletely processed and therefore aberrant. The polymerase chain reaction (PCR) was used to map the sites of the intron/exon junctions and demonstrate further possible splice variants of CD46. The alternative RNAs for CD46 may correlate to the different isoforms of CD46 found in different tissues, tumors, and in serum.

Virus-neutralizing and passively protective monoclonal antibodies to infectious bursal disease virus of chickens

Murine monoclonal antibodies (MAbs) were produced to assist in the identification and characterization of the virus-neutralizing epitopes of infectious bursal disease virus (IBDV). Only MAbs that reacted in Western blotting with viral protein 2 (VP2) or immunoprecipitated VP2 neutralized the infectivity of the virus in cell culture and passively protected young chickens from infection. Three of the neutralizing MAbs did not react with denatured viral proteins. Additivity enzyme-linked immunosorbent assays indicated that the six virus-neutralizing MAbs recognized two spatially independent epitopes. The ability of two of the virus-neutralizing MAbs to neutralize a variant of IBDV that had escaped neutralization by all the other MAbs confirmed the existence of two distinct neutralizing epitopes. The results support the hypothesis that there are at least two non-overlapping epitopes recognized by the virus-neutralizing MAbs reported in this study, although these may still be within one conformational site on VP2 of IBDV.

Pregnancy-induced hypertension: recurrence rate in second pregnancies

OBJECTIVE

The purpose of this study was to estimate the rate of recurrence of pregnancy-induced hypertension in an Australian population.

DESIGN

Case records of women with hypertension during pregnancy who were delivered at our hospital during a two-year period were examined retrospectively. Those who had pregnancy-induced hypertension and records of subsequent pregnancies at our hospital were examined for recurrence of proteinuric or non-proteinuric pregnancy-induced hypertension in their second pregnancy.

SETTING

A Sydney teaching hospital with approximately 2500 obstetric deliveries per year.

PARTICIPANTS

Pregnancy-induced hypertension was defined as diastolic blood pressure above 90 mmHg after 20 weeks' gestation in a nullipara who had normal blood pressure before 16 weeks' gestation, with no known history of hypertension or renal disease and whose blood pressure returned to normal postpartum. Case records of 610 women were examined; 236 had records of a second pregnancy at our hospital and of these 140 had pregnancy-induced hypertension.

MEASUREMENT AND MAIN RESULTS

Of these 140 women 50% had a normotensive second pregnancy (95% CI, 42%-58%), 47% again developed pregnancy-induced hypertension (95% CI, 39%-55%) and 3% (95% CI, 0%-6%) had developed chronic, probably essential, hypertension before their second pregnancy. Proteinuric pregnancy-induced hypertension occurred in 14% of first but only 4.5% of second pregnancies (chi 2(1) = 4.711, df = 1, P less than 0.05).

CONCLUSIONS

Although these data are limited by retrospective gathering, it is clear that there is a high recurrence rate of pregnancy-induced hypertension in Australia. However, the risk of having proteinuric pregnancy-induced hypertension, a more severe form of this disorder, diminishes in a second pregnancy.

Urinary tract dilatation in pregnancy

Right-sided ureteral and renal pelvis dilatation was observed during routine uterine ultrasonographic examination at 30 weeks' gestation. This continued to progress with the renal pelvis measuring 8.9 cm in diameter at 35 weeks, leading to early delivery. Renal function remained normal and these changes resolved completely after delivery.

Renal angioplasty for renovascular disease: a reappraisal

The exact role of percutaneous transluminal angioplasty (PTA) for the treatment of renal artery stenoses (RAS) remains unclear. Therefore we analysed the outcome of unselected renal artery PTA in 30 subjects with angiographically proven unilateral RAS (Group I) compared with that of 19 who had RAS but were treated medically (Group II) and 21 who had essential hypertension but who underwent angiography (Group III). Good blood pressure control was achieved in all three groups but those who underwent PTA had a small but significant fall in their requirement for antihypertensive medications (p less than 0.05). However, no patient was "cured" of hypertension and blood pressure was able to be controlled in both Group II and Group III subjects without an increase in their number of antihypertensives. Serum creatinine did not improve significantly during follow-up in those who underwent PTA and was not different from that of Group II subjects at follow-up. Although unselected renal artery PTA for RAS may make blood pressure control easier it does not delay or prevent further deterioration in renal function and should not be used for this purpose.

Circulating levels of tumor necrosis factor and interleukin-1 in cystic fibrosis

To assess the role of tumor necrosis factor (TNF) and interleukin-1 (IL-1) in the pathophysiology of cystic fibrosis (CF)-associated growth failure/cachexia and lung disease we measured height, weight, triceps skin fold, forced vital capacity, forced expiratory volume in 1 second, and plasma levels of TNF, interleukin-1-alpha (IL-1 alpha), interleukin-1-beta (IL-1 beta), and alpha-1-antitrypsin (A1AT) in 12 patients with CF, and in 12 age- and gender-matched healthy controls. The patients as a group had significantly lower values for the anthropomorphic measurements and lung function parameters as compared to controls. They also had higher circulating levels of A1AT than controls. TNF, however, was detected less frequently in patients than in controls. Neither group had detectable levels of circulating IL-1 alpha or IL-1 beta, which is consistent with the observation that CF patients infrequently present with fever. Potential explanations for these findings include compartmentalization of secreted TNF/IL-1, altered regulation of TNF/IL-1 secretion as a result of the chronic inflammatory state seen in CF, or increased degradation of TNF/IL-1, also a result of chronic inflammation. The role of these cytokines in the pathophysiology of CF remains unclear, but should be explored further; however it seems unlikely that circulating TNF plays a role in the growth failure/cachexia associated with CF.

Chicken liver Pz-peptidase, a thiol-dependent metallo-endopeptidase

Pz-peptidase was purified from chicken liver as a protein of Mr 80,000 and pI 5.2. The purified enzyme hydrolysed phenylazobenzyloxycarbonyl-Pro-Leu-Gly-Pro-D-Arg, 2,4-dinitrophenyl-Pro-Leu-Gly-Pro-Trp-D-Lys. 7-methoxycoumarin-3-carboxylyl-Pro-Leu-Gly-Pro-D-(2,4-dinitropheny l)Lys, benzoyl-Gly-Ala-Ala-Phe-p-aminobenzoate, Ac-Ala4 (at the Ala-1-Ala-2 bond) and bradykinin (at the Phe-5-Ser-6 bond). No hydrolysis of proteins was detected. Loss of activity in the presence of EDTA or 1,10-phenanthroline was time-dependent. Metal ions found to restore activity after treatment with EDTA were Zn2+, Mn2+, Ca2+, Co2+ and Cd2+, in decreasing order of effectiveness. Ni2+, Fe2+ and higher concentrations of Zn2+ were inhibitory. Inhibition by N-[1-(RS)-carboxy-3-phenylpropyl]-Ala-Ala-Tyr-p-aminobenzoate and related compounds showed Ki values (down to 5 nM) somewhat lower than those for the rat enzyme. Pz-peptidase was activated by low concentrations of 2-mercaptoethanol and dithiothreitol, but inhibited by higher concentrations. p-Chloromercuribenzoate and some other thiol-blocking reagents were inhibitory. Inactivation by diethyl pyrocarbonate that was reversible by hydroxylamine showed the presence of essential histidine residue(s). We conclude that chicken Pz-peptidase is a metallo-endopeptidase with thiol-dependence. Moreover, the properties of chicken Pz-peptidase agree with those described for mammalian soluble metallo-endopeptidase and endo-oligopeptidase A. consistent with the view that these three types of activity are all attributable to the single enzyme for which the name thimet peptidase has been proposed.

Uteroplacental Doppler ultrasound in routine antenatal care

Three hundred and five pregnant women referred consecutively from a single antenatal clinic for imaging ultrasound after 26 weeks' gestation had doppler velocimetry of umbilical artery, uterine artery and umbilical vein. Results of doppler studies were not available to clinicians until after delivery and clinical case records were examined postpartum for the development of pregnancy-induced hypertension (PIH) or gestational diabetes mellitus (DM) and for fetal outcome. Accurate data were available for 272 women, of whom 167 had a normal pregnancy, 61 had or developed PIH and 44 had or developed DM. None of the various doppler velocimetry measurements differed significantly amongst these 3 groups at any gestational stage. Abnormal values for doppler systolic: diastolic (A/B) ratio were found in only 7% of umbilical artery measurements, 6% of uterine artery measurements and none of umbilical vein measurements. Specificity of abnormal results for PIH or DM was high (95-97%) but sensitivity low (16-17%) and positive and negative predictive values were generally low. Two perinatal deaths occurred and umbilical artery A/B ratio was abnormal in both cases. This study shows that there is a low yield of abnormal results for doppler velocimetry of umbilical artery, uterine artery or umbilical vein in routine antenatal screening.